I have invested about $50 in a name that I have been running with (between buying a few domain names and a phone number). I've been running with it for about 2 weeks now. I just found another business with a similar name.
The difference: I provide web hosting for a niche audience and they provide ads (they're an ad network) for websites for my niche audience. There is 1 letter difference, and if you say the name out loud, they could be spelled either way.
Should I change the name? Kind of stinks because I've already fallen in love with it (somewhat)... and I've already decided to run with it and not overthink things... but I guess I fell short on this.